The art of purification of solids, i.e. the separation of mixtures of solids is an ancient art in chemistry which was known to the alchemist. Although the process is greatly accelerated via being operated at reduced pressure and high temperature, the sublimation of ice from frozen surfaces in winter is well established. A number of glass devices are currently available from all glass companies which can be loaded with a small quantity of a material to be sublimed, the device suitably heated while under vacuum and the solids will collect in the upper cool portion. Such devices do not have provisions for a well defined thermal gradient within the device, nor is there provision for collecting fractions or for monitoring, via spectroscopic techniques, the progress of the process. As a result of these limitations, the glass sublimers are of limited value.
Another device widely used to separate mixtures of solids is HPLC (high performance liquid chromatography), which is very effective but the separated components of the mixture are obtained as dilute solutions. The solvents must be evaporated to give the desired solids. This means that large quantities of volatile solvents must be disposed of. By contrast, my invention is environmentally friendly and produces no solvent or gas to dispose of.